1. Field of the Invention
The present invention relates to an apparatus for providing a user in a vehicle with information about situations around the vehicle detected on the basis of outputs from a plurality of sensors.
2. Description of the Related Art
As an apparatus for providing a user in a vehicle with information about situations around the vehicle detected on the basis of output from a plurality of sensors, a technique of detecting a vehicle around the user's own vehicle by using a camera or a radar and presenting information about the detected vehicle to the user is known (e.g., Japanese Unexamined Patent Application Publication No. 7-332966). Also, a technique of using a plurality of radars to detect a vehicle is known (e.g., Japanese Unexamined Patent Application Publication No. 4-238285).
In such an apparatus, even if some of the plurality of sensors fail, information about the situation around the vehicle continues to be provided to the user on the basis of the other sensors. Therefore, the user wrongly believes that the apparatus operates normally.
However, the above-described apparatus has the following problems.
For example, assume that the apparatus includes a right radar to explore the right side of the vehicle and a left radar to explore the left side of the vehicle. Further, assume that a warning of the approach of another vehicle from the right is performed on the basis of an output from the right radar and that a warning of the approach of another vehicle from the left is performed on the basis of output from the left radar. In this case, if the left radar fails and if the warning of the approach of another vehicle from the right is continued on the basis of output from the right radar, the user wrongly believes that the apparatus operates normally. This causes the wrong perception by the user that no vehicle approaches from the left, because a warning is not provided even when a vehicle actually approaches from the left.
On the other hand, if no information about the vehicle's surroundings is provided to the user when some of the plurality of sensors fail, a wrong perception by the user can be prevented. In this case, however, even information that normally can be provided is not provided to the user, so that the convenience of the apparatus for the user deteriorates.